Let’s see if I can keep this simple: Fireflies in the Garden unfolds across two time frames. At some vague point in the ‘80s, Michael (Cayden Boyd) is often made miserable by his overbearing father, Charles (Willem Dafoe), and then consoled by his saintly mother, Lisa (Julia Roberts). That summer, they’re to be joined by Jane (Hayden Panettiere), Lisa’s sister and Michael’s aunt, though she skews much closer in age to her nephew than her sibling, and she gets to witness firsthand their dysfunctional family dynamic.

Now, in the present, Michael (Ryan Reynolds) has made more of a living as an author than his father had — albeit, by cranking out generic romance novels — and he’s finally returned home for Mom’s graduation from college. However, before they can be reunited, Mom dies in a car accident caused by Charles’ sudden effort to swerve and avoid one of Jane’s two kids as he chases a ball into the street.

I know. What timing, what odds. So we’re left with Michael back home once more, still mad at Dad, in addition to discovering secrets about his late mother, nursing a separation from his wife (Carrie-Anne Moss), and trying to appease the now-responsible Jane (Emily Watson), who’s unhappy with Michael’s latest manuscript — a departure from the bill-paying fluff that incorporates many of their own childhood woes.

Writer-director Dennis Lee clearly wants to steep his audience in a realistically tangled web of relationships, but the conflicts that unfold do so with the inevitable, if relatively understated, weight of melodramatic determination. Reynolds helps lend some trademark warmth to the proceedings — in fact, his Michael’s an awfully charismatic adult when he wants to be, in spite of an exceedingly mopey upbringing (Boyd is saddled with that one note whenever we flash back) — but his equally worthy dramatic chops can’t disguise the shifts in tone that require him to be the ideal Ryan Reynolds in one scene and a real, troubled character all his own the next.

Dafoe is pushed more often than not to the threshold of volatile emotion, to the point where the casting seems to shortchange his character. Despite a litany of motivations — professional inadequacy, survivor’s guilt, a plain old bad temper — Charles is rendered so closely in pitch to something like the Green Goblin that it’s hard to divorce the best intentions of Dafoe and Lee from one’s broadly rendered expectation of said actor’s persona. Roberts, on the other hand, is asked to demonstrate little beyond perpetual sympathy for her son and questionable loyalty to her husband, and it’s into her mouth that Lee forces the simplest platitudes and emotional shortcuts (“I love you big” is always met with “I love you bigger”).

The greatest divide between actors (or, rather, actresses) comes from the Panettiere/Watson pairing; although neither gives a bad performance, they don’t together resemble a full portrait of the girl who grows into this woman. And here’s where the off-camera troubles come in: Lee has admitted that the current cut of Fireflies differs from that which premiered at the 2008 Berlin Film Festival and proceeded to open in other countries while the U.S. distribution fell into legal limbo. As such, when one scene suggests age-appropriate (though bloodline-inappropriate) tensions between the young Michael and the young Jane, it seems like the sole hint as to why adult Jane would lambast adult Michael so severely for what he’s willing to put into his latest novel for public consumption. (A thorough Wikipedia summary of the international cut confirms other excised plot points, none of which would’ve been as scandalous.)

Maybe it’s merely a matter of one scene’s overstated tone; the film is admittedly mawkish overall, but it tends to operate in a low key that doesn’t cause for too much tear-jerking or eye rolling. Some performances are tender, while others come on a bit too strong. Some characters seem incomplete, while others seem entirely superfluous to the plot. Gentleness be damned, the emotional effectiveness of Fireflies on the Garden varies from moment to moment between not pushing too hard or simply not pulling hard enough.